TilS (tRNAIle lysidine synthetase) is an essential, ATP-dependent enzyme which is conserved in bacterial pathogens. The high degree of conservation of TilS among pathogenic bacteria combined with its absence in human nuclear and mitochondrial genomes make it an attractive potential target for novel antibacterial drugs.
With this in mind scientists at AstraZeneca created a screening platform which is described in the recent Journal of Biomolecular Screening article entitled: ‘Discovery of ATP-Competitive Inhibitors of tRNAIle Lysidine Synthetase by High-Throughput Screening’. To enable this screening these scientists used ATP linked with either the fluorophore BODIPY or TAMARA. Binding of the labeled ATP to TilS enzymes from E. coli and S. aureus could be measured by an increase in fluorescence anisotropy and treatment with an ATP-competitive inhibitor would displace the labeled ATP leading to a decrease in fluorescence anisotropy.
We at BMG are happy that our PHERAstar HTS microplate reader could be used in this novel screening approach!